Performance of missing transverse momentum reconstruction with the ATLAS detector using proton–proton collisions at $$\sqrt{s}=13~\hbox {TeV}$$ s = 13 TeV

Abstract

The performance of the missing transverse momentum ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>E</mml:mi> <mml:mrow><mml:mi>T</mml:mi></mml:mrow> <mml:mi>miss</mml:mi></mml:msubsup> </mml:math> ) reconstruction with the ATLAS detector is evaluated using data collected in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV in 2015. To reconstruct <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>E</mml:mi> <mml:mrow><mml:mi>T</mml:mi></mml:mrow> <mml:mi>miss</mml:mi></mml:msubsup> </mml:math> , fully calibrated electrons, muons, photons, hadronically decaying <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>τ</mml:mi> <mml:mtext>-leptons</mml:mtext></mml:mrow> </mml:math> , and jets reconstructed from calorimeter energy deposits and charged-particle tracks are used. These are combined with the soft hadronic activity measured by reconstructed charged-particle tracks not associated with the hard objects. Possible double counting of contributions from reconstructed charged-particle tracks from the inner detector, energy deposits in the calorimeter, and reconstructed muons from the muon spectrometer is avoided by applying a signal ambiguity resolution procedure which rejects already used signals when combining the various <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>E</mml:mi> <mml:mrow><mml:mi>T</mml:mi></mml:mrow> <mml:mi>miss</mml:mi></mml:msubsup> </mml:math> contributions. The individual terms as well as the overall reconstructed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>E</mml:mi> <mml:mrow><mml:mi>T</mml:mi></mml:mrow> <mml:mi>miss</mml:mi></mml:msubsup> </mml:math> are evaluated with various performance metrics for scale (linearity), resolution, and sensitivity to the data-taking conditions. The method developed to determine the systematic uncertainties of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>E</mml:mi> <mml:mrow><mml:mi>T</mml:mi></mml:mrow> <mml:mi>miss</mml:mi></mml:msubsup> </mml:math> scale and resolution is discussed. Results are shown based on the full 2015 data sample corresponding to an integrated luminosity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>3.2</mml:mn> <mml:mspace></mml:mspace> <mml:msup><mml:mtext>fb</mml:mtext> <mml:mrow><mml:mo>-</mml:mo> <mml:mn>1</mml:mn></mml:mrow> </mml:msup> </mml:mrow> </mml:math> .